People are wearing safety pins on their clothes in a show of solidarity against racism

If you’re out and about today, you might notice a few people around you wearing an unusual accessory on their top: a silver safety pin.

But it’s not a low-key resurgence of punk fashion. Instead, it’s a sign of solidarity with the UK’s immigrant population.

The brilliantly simple campaign was started by an American woman living in London, who gave her name as Allison in an interview with i100.

She was appalled at the news that reports of racist and xenophobic attacks have risen since the UK voted to leave the EU last week. In a string of posts on Twitter, she suggested that people should wear a safety pin to show that they are united against racism – and to indicate to potential victims of racist abuse that they will support them.

She wrote: “So I have an idea similar to #ridewithme to help protect those being abuse as result of Brexit referendum – but I need your help. The idea being that anyone against the sort of nationalistic, racist violence we’ve been seeing could identify themselves as a ‘safe’ ally.

“I’d like to come up with something that can be made by anybody anywhere to pin on their jacket or coat to signify that they are an ally,” she continued. “A safe person to sit next to on a bus, walk next to on a street, even have a conversation with.

“I quite like the idea of just putting a safety pin, empty of anything else, on your coat. A literal SAFETY pin!”

The inspiration came from a spontaneous campaign that took place in Australia in 2014, shortly after a Muslim gunman took 18 people hostage in a Sydney cafe. In a show of support for ordinary Muslims who were afraid of subsequently being the target of racist abuse, people wore stickers saying “I’ll ride with you” on public transport.

Since Allison’s initial posts on 26 June, the campaign – organised under the hashtag #SafetyPin – has gone viral, with 17,300 people tweeting about it at the time of writing. Hundreds of people have been sharing photos of themselves wearing a safety pin to spread the message.

There was a 57% rise in reports to an online hate-crime reporting site between Thursday and Sunday last week (covering the referendum on Thursday and the result on Friday) compared to the previous month, according to the National Police Chiefs’ Council.

It was reported yesterday that an 11-year-old girl had been racially abused in Sussex, in an incident that police are linking to the referendum result. Other schoolchildren have been racially abused in west London, according to Labour politician Seema Maltotra.

“Someone shouted: ‘Why are there only 10 white faces in this class? Why aren’t we educating the English?’” she said on Saturday, citing a letter from one of her constituents in Hounslow. “Another went close up to the children and said: ‘You lot are taking all our jobs. You’re the problem. You’re taking our jobs, you’re taking our land.”’

She added that children as young as six were crying because they were afraid they would have to leave the country.

In another Twitter post, Allison addressed the need to unite against all forms of racism, not just attacks against EU nationals. “Hey #safetypin supporters, there’s a group of people I’ve been really remiss in not mentioning yet: the BAME [Black Asian and Minority Ethnic] folks of Britain,” she wrote. “British citizens who have lived in the UK for generations are just as at risk as EU nat’ls or recent immigrants to face abuse or violence.”